/**
 *function-icon
 */
.function-icon{
    z-index: 1;
    position: absolute;
    display: inline-block;
    width: 30px;
    height: 30px;
    left: 50px;
    top: -10px;
    background: transparent;
}

.function-icon .function-icon-constant{
    background-image: url(../images/systemPage/icon/icon-function-inputoutput.png);
    background-size: 80%;
    background-repeat: no-repeat;
    background-position: 50%;
    width: inherit;
    height: inherit;
}

.function-icon .function-icon-sigmod{
    background-image: url(../images/systemPage/icon/icon-function-sigmod.png);
    background-size: 40%;
    background-repeat: no-repeat;
    background-position: 50%;
    width: inherit;
    height: inherit;
}